Electrode, and fuel cell and water treatment equipment each using same

Abstract

An electrode includes a first diffusion layer ( 11 ) having water repellency and functioning to diffuse oxygen, and a second diffusion layer ( 13 ) supporting a catalyst layer ( 30 ) thereon and functioning to diffuse oxygen. The electrode further includes an electrically conductive layer ( 12, 15 ) including a metal material ( 20, 21 ) and an oxygen-permeable material, and interposed between the first diffusion layer and the second diffusion layer. A fuel cell ( 100 ) and a water treatment equipment each include: an anode ( 3 ); an ion transfer layer ( 4 ) having proton permeability; and a cathode ( 1, 2 ) being the electrode described above, and separated from the anode with the ion transfer layer interposed therebetween.

The invention claimed is: 
     
       1. An electrode comprising:
 a first diffusion layer having water repellency and functioning to diffuse oxygen; 
 a second diffusion layer supporting a catalyst layer thereon and functioning to diffuse oxygen; and 
 an electrically conductive layer including a metal material and an oxygen-permeable material, the electrically conductive layer interposed between the first diffusion layer and the second diffusion layer, the metal material being dispersed in the oxygen-permeable material, 
 wherein ingredients of the metal material are electrically connected to each other inside the electrically conductive layer, and 
 wherein the electrically conductive layer has an oxygen transmission rate of 10,000 cc/m 2 ·24 h·atm or greater and 720,000 cc/m 2 ·24 h·atm or less. 
 
     
     
       2. The electrode according to  claim 1 , wherein the electrically conductive layer has electrical resistivity of 2 Ωm or less. 
     
     
       3. The electrode according to  claim 1 , wherein the oxygen-permeable material is silicone. 
     
     
       4. The electrode according to  claim 1 , wherein the metal material has a particle shape. 
     
     
       5. The electrode according to  claim 1 , wherein the metal material has a flake shape or a wire shape. 
     
     
       6. The electrode according to  claim 1 , wherein the electrically conductive layer further includes a carbon material. 
     
     
       7. A fuel cell comprising:
 an anode; 
 an ion transfer layer having proton permeability; and 
 a cathode being the electrode according to  claim 1 , and separated from the anode with the ion transfer layer interposed therebetween. 
 
     
     
       8. The fuel cell according to  claim 7 ,
 wherein the first diffusion layer in the cathode is arranged so as to be brought into contact with gas containing oxygen; and 
 wherein the second diffusion layer in the cathode is arranged so as to be brought into contact with a liquid to be treated including microorganisms. 
 
     
     
       9. The fuel cell according to  claim 8 , wherein the liquid to be treated includes organic matter. 
     
     
       10. The fuel cell according to  claim 7 , wherein the anode is a porous body, or a mesh-like electrically conductive sheet. 
     
     
       11. The fuel cell according to  claim 7 , wherein the ion transfer layer is a porous body, or a nonwoven fabric. 
     
     
       12. A water treatment equipment comprising:
 an anode; 
 an ion transfer layer having proton permeability; and 
 a cathode being the electrode according to  claim 1 , and separated from the anode with the ion transfer layer interposed therebetween. 
 
     
     
       13. An electrode comprising:
 a first diffusion layer having water repellency and functioning to diffuse oxygen; 
 a second diffusion layer supporting a catalyst layer thereon and functioning to diffuse oxygen; and 
 an electrically conductive layer including a metal material and an oxygen-permeable material, and interposed between the first diffusion layer and the second diffusion layer, 
 wherein the electrically conductive layer has electrical resistivity of 2 Ωm or less, and an oxygen transmission rate of 10,000 cc/m 2 ·24 h·atm or greater and 720,000 cc/m 2 ·24 h·atm or less.